Naphtho(1, 2)triazole brighteners for fine fabrics



3,341,530 NAPHTHO(1,2)TRIAZOLE BRIGHTENERS FOR FINE FABRICS Albert F.Strobel, Delmar, and Sigmund C. Catlno, Castleton, N.Y., assignors toGeneral Aniline 81 Film Corporation, New York, N.Y., a corporation ofDelaware No Drawing. Filed May 24, 1965, Ser. No. 458,369

12 Claims. (Cl. 260-240) This application is a continuation-in-part ofour applications Ser. Nos: 40,197, filed July 1, 1960, now abandoned;113,575, filed Mar. 31, 1961, now abandoned, and 185,189, filed Apr. 5,1962, now abandoned.

This invention relates to a new class of fluorescent naphthotn'azolecompounds possessing new and useful properties which render themparticularly useful as fluorescent optical bleaching or whitening agentsfor fine fabrics, such as nylon, Dacron, Orlon and the like.

It is well established that textiles tend to develop a yellowish shadeon ageing which cannot be removed by ordinary methods of bleaching orwashing. The heretofore used methods of blueing white materials withblue pigments or fugitive blue dyestufis have become quite obsolete inmodern laundry practice and have been largely superceded by methodsemploying fluorescent optical bleaching agents or brighteners asadditives to the soap or detergent in the washing bath. Thesebrightening agents are usually conveniently supplied commercially in theform of intimate admixtures with the soap or detergent in bars, flakes,powders, etc. The fluorescent optical bleaching agents perform theirdesired function by virtue of their characteristic absorption ofultraviolet radiations and subsequent conversion of this energy to lightenergy within the visible spectrum. This converted and emitted lightenergy tends to neutralize any yellowness of the material and therebyincrease the apparent whiteness thereof.

It is known that blue-fiuorescing 2-(4-styrylphenyl)-2H-naphtho[l,2]triazole compounds (containing a sulfonic acid group inthe stilbene nucleus) can be used from a neutral to a weakly acid bathfor the brightening of wool and cellulose fibers. None of them, however,have appreciable afiinity for the synthetic fibers such as Dacron andOrlon made from terephthalic acid and ethylene glycol, acrylonitrile,etc. The lack of afiinity is probably due to the fact that the finefabrics like Dacron and Orlon, being strongly hydrophobic materials, arenot penetrated by these relatively water soluble sulfonated products.

It is also known that the sulfonic acid substituent in the stilbenenucleus of the above foregoing2-(4-styrylphenyl)-2H-naphtho[1,2]triazoles can be replaced by cyano,sulfone and sulfonamide groups to produce optical brightening agentswhich are useful for example in brightening paraflin, polymericsynthetic materials such as polymeric amides from ethylene diamine andadipic acid, polyvinyl chloride, polyacrylonitrile, polyacrylic acidesters and copolymers of these materials, cosmetic preparations,ointment bases and the like.

United States Patent 2,784,183 pertains to brighteners which havesulfonic acid or other ionic substituents as an integral part of themolecule. We have found that the ionic compounds of this patent do nothave afiinity for line fabrics like Dacron and Orlon.

Even when the ionic groups which are present in these compounds aresubstituted by a non-ionic nitrile group, as in United States Patent2,972,611, the non-ionic compounds do not have outstanding aflinity forfine fabrics.

We have now discovered that certain fluorescent naphthotriazoles, freefrom sulfonic and carboxylic acid groups as well as cyano, sulfone andsulfonamide groups, are

intone m-r 3,341,530 Patented Sept. 12, 1967 "ice readily incorporatedin specified amounts into polyamides (nylon), polyesters (e.g., Dacron),polyvinyl chloride, polyvinylidene chloride, polystyrene, polyurethane,polyethylene, polyacrylonitrile (e.g., Orlon), and similar film, fiberand fabric forming materials as effective brightening agents. These newfluorescent naphthotriazoles are especially unusual in that they havegreat affinity for nylon, and superior brightening power on nylon overthe corresponding sulfone and sulfonamide substituted2-(4-styrylphenyl)-2H-naphtho[1,2]triazoles as well as cyano substitutedderivatives of the same. In fact, we have found that these newfluorescent naphthotriazoles have exceedingly high brightness andwhitening power in melt application on ethylene glycolterephthalic acidpolyester fabric of any brightener we have experimented with, either ofour own synthesis or with competitive products. In this connection, itis interesting to note that these fluorescent naphthotriazoles areoutstanding on nylon, and are particularly adaptable on films, fibersand fabrics made from polyvinyl chloride, polyvinylidene chloride,polystyrene, polyethylene, polymethyl methacrylate, cellulose nitrateand polyurethane.

The fluorescent naphthotriazoles, i.e., 2-(2-carbamyl-4-styrylphenyl)-2H-naphtho[1,2]triazoles prepared in accordance with thepresent invention are characterized by the following general formulae:

wherein R and R represent either hydrogen, halogen such as chlorine,bromine, iodine or fluorine, lower alkyl such as methyl, ethyl, propyl,isopropyl, butyl, isobutyl and lower alkoxy such as methoxy, ethoxy,propoxy, butoxoy, isobutoxy, cyclohexyloxy, and the like. R representseither hydrogen, alkyl, such as methyl, ethyl, propyl, butyl, cyclohexyl, etc., dialkylamino alkyl, such as dimethyl aminoethyl, dimethylaminopropyl, dimethyl aminobutyl, diethyl aminobutyl, dipropylaminoethyl, dipropyl aminobutyl, dibutyl aminoethyl, dibutyl aminobutyl,dicyclohexylaminoethyl, dicyclohexylaminopropyl, dicyclohexylaminobutyl,etc., morpholino-N-alkyl and piperidino-N-alkyl, wherein the alkyl groupcontains from 2 to 4 carbon atoms, or hydroxyalkyl, e.g., hydroxyethyl,hydroxypropyl, hydroxybutyl, etc., R represents an alkyl group of from 1to 4 carbon atoms such as methyl, ethyl, propyl, isoproyl, butyl,isobutyl, hydroxyalkyl of the same value as in R and the like, and Rrepresents the atoms necessary to complete a 5- or 6- memberedheterocyclic ring system with the nitrogen atom and selected from theclass consisting of morpholino,

3 piperidino, hexamethyleneimino, pyrrolidino, imidazolo, pyrazolo,1,2,3-triazolo, 4-pyridono, -piperidono, and the like.

The unsubstituted carboxamide is prepared by diazotizing a stilbene ofthe formula:

R1 CONH:

wherein R and R have the same values as above, in glacial acetic acidadding hydrochloric acid and sodium nitrite to the amine as a solutionor suspension in water or hydrochloric acid. After diazotization iscomplete, 2- napthylamine, as the hydrochloride or as a slurry, is addedto the diazo in equimolar amount. After coupling has occurred, themonoazo dye is oxidized to the triazol, for example, by heating withcopper sulfate in a basic solvent such as pyridine or ,8,a-picoline, andthe like. The brightener is isolated by first precipitating andfiltering the copper as the sulfide and then separating from the solventeither by steam distillation or dilution with water and cooling, andthen filtering. The substituted carboxamides are prepared by diazotizinga stilbene of the formula:

wherein R and R have the same values as above, in acetic acid by addingthereto hydrochloric acid and sodium nitrite, preferably in aqueoussolution, to the amine at a temperature of -10" C. After diazotizationis complete, Z-naphthylamine, as the hydrochloride or as a slurry, isadded to the diazo in equimolar amount, care being exercised that thereaction remains weakly acid. After coupling has occurred, the monoazodye is oxidized to the triazole, for example, by heating with coppersulfate in a basic solvent such as pyridine or ,6,a-picoline, and thelike. The resulting compound is then treated with thionyl chloride or amixture of phosphorous oxychloride and phosphorus pentachloride in theknown manner to convert the carboxylic acid group to the acid chloride.The latter is then further reacted with an appropriate amine in theknown manner to give products shown by Formulas l and 2 above.

Alternatively, the fluorescent substituted carboxamido naphthotriazolesof the present invention are prepared from the intermediates of thefollowing formula:

CH=CH -No.

n, doNH-R, Q Q

CH=CH No,

R1 ON(R4): and

wherein R R R R and R have the same values as above by reducing thenitro group to the amino group, diazotizing and coupling withZ-naphthylamine and then oxidizing the thus formed azo dye to form thetriazole compound.

The stilbene intermediates characterized by Formulae a, b and c areprepared in accordance with the method of Pfeiifer, Berichte, 44, 1119,by condensing the methyl ester of S-nitro-o-tolucarboxylic acid withanyone of the following benzaldehydes:

benzaldehyde 0-, m-, and p-bromobenzaldehyde 0-, mandp-chlorobenzaldehyde 4 2,3-, 2,4-, 3,4- and 2,6-dichlorobenzaldehyde 0-,mand p-tolualdehyde S-bromo-Z-methoxybenzaldehyde5-chloro-2-methoxybenzaldehyde 2-methovy-m-tolualdehydeS-methoxy-o-tolualdehyde 3-bromo-4-cthoxybenzaldehyde4-butoxy-3-chl0robenzaldehyde 0-, mand p-methoxybenzaldehyde2,4-dibromobenzaldehyde 0-, mand p-ethoxybenzaldehyde3,4-diethoxybenzaldehyde o-, mand p-propoxybenzaldehyde2,3-dimethoxybenzaldehyde o-, mand p-butoxybenzaldehydep-fluorobenzaldehyde 4-chloro-o-tolualdehyde 3-chloro-p-tolualdehyde2,4-, 2,5- and 3,5-dimethylbenzaldehyde 4- and5-isopropyl-o-tolualdehyde 2,4- and 2,5-diethylbenzaldehydep-tertiarybutylbenzaldehyde p-ethylbenzaldehyde p-iodobenzaldehyde Theforegoing condensation products which contain a carboxylic acid group inthe 2-position and a nitro group in the 4-position of the stilbenenucleus are then converted to the corresponding acid chlorides in theknown manner, i.e., by treatment with thionyl chloride and finallyreacting the latter with an appropriate amine in the conventional way.The resulting product is then subjected to the reduction of the nitrogroup to yield the 4-amino stilbene derivative. The resulting aminostilbene intermediate is then further treated by diazotization andcoupling, followed by oxidation as will be noted from the followingexamples.

Alternatively, the stilbene intermediates characterized by Formulae a, band 0 may be prepared by the reaction of the appropriate benzaldehydewith the appropriate 5- nitro-o-toluamide according to the method ofMacovski, Georgescu and Bachmeyer, Ben, 74B 1279-84 (1941); Chem.Abstracts, 36, 4813 (1942). The resulting product is then subjected tothe reduction of the nitro group to yield the 4-aminostilbenederivative. The resulting aminostilbene intermediate is then furthertreated by diazotization and coupling, followed by oxidation to thetriazole compound.

The unsubstituted carboxamido nitro stilbene intermediate may beprepared most efiicaciously by condensing S-nitro-o-tolunitrile with anyof the foregoing benzaldehydes whereby the nitrile is converted in thereaction to a CONH group. The nitro group in the 4-position of thestilbene nucleus is further treated, as above, to reduce it to an aminogroup.

As examples of organic amines which may be reacted with the carboxylicacid chloride substituted naphthotriazoles or the 4-amino stilbenederivatives, the following are illustrative:

Methylamine Ethylamine Propylamine Butylamine DimethylaminoethylamineDimethylaminopropylamine Dimethylaminobutylamine DiethylaminoethylamineDiethylaminopropylamine Diethylaminobutylamine DipropylaminoethylamineDipropylaminopropylamine Dipropylaminobutyl amine DibutylaminoethylamineDibutylaminopropylamine Dibutylaminobutylamine MorpholinoaminoethylamineMorpholinoaminopropylamine MorpholinoaminobutylaminePiperidinoaminoethylamine Piperidinoarninomethylamine DimethylamineDiethylamine Dipropylamine Dibutylamine Imidazole Morpholine Piperidine1,2-dihydropyridine Pyrrolidine -Piperidone 4-pyridone Pyrazole 1,2,3-tn'azole 2-aminoethanol l-amino-Z-propanol 2,2'-iminodiethano1 Inconnection with the naphthotriazoles of Formulas 1, 2 and 3, it is to benoted that those which have an ionic substituent in the 3-position ofthe 4-styrylphenyl configuration, such as, for example,

are water soluble and dye both nylon and Orlon. Those which do notcontain a water solubilizing group, such as CONH CONl-I=alkyl, are waterinsoluble and dye nylon and Dacron. Those fluorescent dyes which containa hydroxyl solubilizing group such as, for example, -CON1-IC H OH aremore water soluble and dye nylon preferentially.

The brightening agents of this invention are applied either from anaqueous textile bath or by melt incorporation into the aforementionedfilm, fibre and fabric-forming polymers. As to fabrics, the brighteningagents may be applied in dispersed form. The dispersion may be made bykneading the brightener with a suitable dispersing agent in aWerner-Pfleiderer mixer, or it may be dispersed by dissolving thebrightener in a suitable solvent and pouring the solution into watergiving a finely divided precipitate. The dispersed brightener is usuallyapplied to the fabric by heating in water together with the fabric forabout 45 minutes at a temperature near the boil. The amount ofbrightener may vary a great deal, and in fact may range from 0.0035% to0.5% based on the weight of the fiber.

The following examples will serve to illustrate the present inventionwithout being deemed limitative thereof. Parts are by weight unlessotherwise indicated.

EXAMPLE I JONH:

The intermediate having the formula:

H H Cl C=C NO:

( JONH:

6 This mixture is shaken well and allowed to stand in a closed vesselfor several days. The charge is filtered, and the presscake washed onthe funnel with 100 ml. of glacial acetic acid. The cake is, ground in amortar with 50 mls. of glacial acetic acid, filtered, washed with anadditional 50 mls. of glacial acetic acid and finally washed with 100mls. of water and dried in air to yield the crude intermediate. Themelting point of this product is 272.5 C.

All of the above crude nitro intermediate is slurried in about 500 mls.of 1% aqueous sodium hydroxide solution at 70 C., filtered and thenwashed with 200 mls. of water. The resulting cake is once morereslurried in 500 mls. of 1% aqueous sodium hydroxide solution at 70 C.,filtered, washed with 500 mls. of water and dried at C. in air to givethe yield of 46 grams of the intermediate.

The nitro intermediate as obtained above is reduced to the amine in thefollowing manner:

Into a 1-liter flask are charged 110 mls. of dimethyl formamide, 55 mls.of water, 39 grams of iron borings 60 mesh, and 6.7 mls. of concentratedhydrochloric acid. The material is then heated for 10 minutes at 95 C.and a solution of 30.2 grams of the reslurried nitro material obtainedas above in 150 mls. of dimethyl formamide was added in small portionsat 100 C. The product was heated for 1 hour at 107-l10 C. The charge isthen neutralized with soda ash to a negative test with potassiumferricyanide or phenolphthalein alkalinity. The charge is filteredthrough super cel at 108 C. and the cake washed with 200 mls. of hotdimethyl formamide. The filtrate is then diluted to 4 liters volume withwater, filtered and washed with additional 2 liters of water and thenair dried to give 24 grams of amine product.

11.8 grams of the amine product is dissolved at 80 C. in 300 mls. ofglacial acetic acid and a solution of 21 mls. of concentratedhydrochloric acid in 75 mls. of water is added. The resulting charge iscooled to 0 C. and 8.6 mls. of sodium nitrite solution (38.5% wt./vol.)(=.047 mole) is added dropwise to the amine hydrochloride slurry at 0-5C. and stirred for A hour at 5-10 C., followed by addition of 3 mls. of10% aqueous sulfamic acid solution to destroy excess nitrous acid. Asolution of 6.75 grams of 2-naphthylamine is dissolved at C. in 250 mls.of water and 8.4 mls. of concentrated hydrochloric acid, filtered bygravity and added slowly to the diazo at 0-5 C. the resulting slurry isstirred for 2 hours at 0-10 C. and then the charge filtered and the cakewashed with 1 liter of cold water.

The resulting dyestuff after drying is dissolved at 85 C. in 2400 mls.of picoline and at a temperature of C. a solution consisting of 27.2grams of copper sulfate in 50 mls. of water is then added. The materialis heated for 2 hours at reflux. The copper is precipitated with sodiumsulfide, 8 filtered at 98 C. and then washed with 250 mls. of picolineat a temperature of 120 C. The combined filtrate and picoline wash iscooled to 5 C. and filtered. Then the brightener cake is washed withmls. of picoline at 0 C., followed by washing with 250 mls. of water.The resulting brightener is dried at 80 C. in air.

In order to determine what brightening effect, if any, the replacementof the carboxylic acid amide group, in the stilbene moiety of thefluorescent naphthotriazole compound prepared as above, by a cyanogroup, a .05% dyeing (O.W.F.) on nylon of the instant compound iscompared with a .05% dyeing of the compound of the formula:

The dyeings are made by dissolving .05 gram of dye in 100 mls. ofdimethyl formamide. 5 mls. of this solution is dissolved in 150 mls. ofan 0.1% aqueous Peregal solution (commercially available surfactant). Agram swatch of nylon is dyed at 100 F. for 45 minutes, rinsed 3 timesand dried.

The reason for a dyeing made at 100 F. is that many women wash theirpersonal clothing in wash basins and other facilities, which is normallyaround 100 F., and not in washing machines where hot water, above 100'F. is generally employed.

Comparative brightness readings are made as follows:

EXAMPLE V Nylon Dyeing at 100 F.

N CI asQ/ O NH:

On nylon at 100 F. compound (1) is far superior to compound (2) despitethe fact that neither of the compounds is ionic. The superiority is verydistinctive by comparative brightness readings. This is whollyunexpected and surprising, since compounds (1) and (2) are both freefrom ionic substituents.

EXAMPLE II N H H Cl CONH: N

Example I is repeated with the exception that 42.2 grams ofp-chlorobenzaldehyde are replaced by 36.0 grams of p-tolualdehyde.

EXAMPLE 111 N aQas N l C O NH: N

Example I is repeated with the exception that 42.2 grams ofp-chlorobenzaldehyde are replaced by 52.5 grams of2,4-dichlorobenzaldehyde.

EXAMPLE IV Example I is repeated with the exception that 42.2 grams ofp-chlorobenzaldehyde are replaced by 40.8 grams ofo-methoxybenzaldehyde.

EXAMPLE VI CHH CONH:

Example I is again repeated with the exception that 42.2 grams ofp-chlorobenzaldehyde are replaced by 31.8 grams of benzaldehyde.

In order to determine what brightening effect, if any, the replacementof the carboxylic acid amide group, in the stilbene moiety of thefluorescent naphthotriazole compound prepared as above, by the cyanogroup, a .05% dyeing (O.W.F.) on nylon of the instant compound iscompared with a .05% dyeing of the compound of the formula:

The dyeings are made by dissolving .05 gram of dye in mls. of dimethylformamide. 5 mls. of this solution are dissolved in 150 mls. of a 0.1%aqueous solution of Peregal O. A 5 gram swatch of nylon is dyed at F.for 45 minutes, rinsed 3 times and dried.

Comparative brightness readings are made as follows:

Nylon Dyeing at; 130 F.

CONH: N K) H H l CN N On nylon at 130 F. compound (3) is far superior tocompound (4) despite the fact that neither of the compounds is ionic.The superiority is very distinctive by comparative brightness readingand also by visual observation. Due to the fact that the square of thebrightness is proportional to the concentration used (30*:900; 25 =625),it requires about 40% more of compound (4) to achieve the same degree ofbrightness as compound (3). This is wholly unexpected, since compounds 1and 3 are both free from ionic substituents. The unexpected superiorityof (3) over (4) on nylon is of great commercial importance.

Furthermore, in order to ascertain the merit of the instant compound ascompared with related ionic substituted compounds 0.05% by weightdyeings are made on Dacron polyester cloth of the instant brightener (3)and the ionic brighteners of the formulae:

(5) 35 N/T soar Q ij =C --N Q Q solNnso n, U

Dacron" Dyeing at On Dacron at 190200 F. compound (3) is far superior tocompounds (5) and (6). The superiority is very distinctive bycomparative brightness readings. This great difference is probably dueto the fact that compound (3) is non-ionic whereas compounds (5) and (6)are ionic,

and compound 3) has much greater affinity for a hydrophobic fiber suchas Dacron than the ionic compounds (5) and (6).

In order to ascertain the merit of this compound against a related ioniccompound on Arnel cellulose triaeetate fiber and cellulose acetate fiber0.01% by weight dyeings are made on Arnel" and also cellulose acetate ofthe instant brightener (3) and ionic substituted brightener (6).

The dyeings are made by dissolving .05 gram of dye in mls. of dimethylformamide. 1 ml. of this solution is dissolved in mls. of a 1% aqueousPeregal 0 solution. A 5 gram swatch of fabric is dyed at l90200 F, for45 minutes, rinsed 3 times and dried.

Arnel" Cellulose Dyeing at Acetate -200 F. D yein r at Compound (3) 1241 Compound (6) 1 20 On both ArneY and cellulose acetate compound (3) isfar superior to compound (6). The superiority is very distinctive bycomparative brightness readings. This very great difference is probablydue to the fact that compound (3) is nonionic whereas compound (6) isionic, and compound (3) has a much greater afiinity for hydrophobicfibers such as ArneF and cellulose acetate than the related ionicsubstituted compound.

Further, in order to determine what brightening effect, if any, thereplacement of the carboxylic acid amide group, in the stilbene moietyof the fluorescent naphthotriazole compound prepared as above, by acarboxylic acid group, a 01% dyeing (O.W.F.) on Dacron" of the instantcompound is compared with a .01% dyeing of the compound of the formula:

2700K L/ i 1 1 Comparative brightness readings are made as follows:

Dacron" Dyeing at 190200 F. (3) 24 3 EXAMPLE VII N CH CHZCHQN Cl ONH;

Example I is again repeated with the exception that 42.2 grams ofp-chlorobenzaldehyde were replaced by 46.4 grams of3-chloro-p-tolualdehyde.

EXAMPLE VIII N H. CEeCH N H; C O N H: N i

Example I is again repeated with the exception that 42.2 grams ofp-chlorobenzaldehyde are replaced by 40.2 grams of2,4-dimethylbenzaldehyde.

Application The application of each of the brighteners of Examples I toVIII inclusive to nylon is carried out by dissolving 0.05 gram of eachbrightener in separate 100 mls. portions of dimethyl formamide. Then ml.of each of the dimethyl forrnamide solutions is added into eightindividual dyebaths containing 100 mls. of water and 0.1% of Peregal O(a commercially available ethylene oxide condensation product) as adispersing agent. Into each of the eight dyebaths a 5 grams swatch ofnylon is entered and the material heated to 135-140 F. for 1 hour, afterwhich it is removed, rinsed with water and dried. The brightness of theeight dyed cloths are then read on an ultraviolet fluorescentphotometer. The brightness reading of each of the brightener compoundsruns on the average between 30 to 43.

Duplicate dimethyl-formamide solutions of each of the brighteners ofExamples I to VIII were prepared and applied to Dacron in the samemanner as above. High brightness readings are obtained on these also.

EXAMPLE D( filtering, the crude product is purified by dissolving in 500grams of N,N-dirnethy1formamide containing 5 grams of animal charcoaland filtering at 100 C. The filtrate is then diluted with 2500 grams ofwater. After filtering and drying, 28.2 grams of4-chloro-N-[3-(N,N-dimethyl)amino propyl] 4 [2(ZH-naphtho[1,2]triazolyl)]-stilbenecarbonamide is obtained as a brightyellow powder which melted at 228.l-229.2 C. uncorrected.

The brightener is applied to polyacrylonitrile fiber (Orlon) as follows:50 mg. of brightener is dissolved in 100 cc. of dimethyl formamide. 5.0cc. of this solution (=.0025 gram of brightener) is added to a dyebathcontaining 145 cc. of 1% acetic acid. A 5.0 g. swatch of Orlon is addedand the dyebath heated and agitated to 190-200 F. for 1 hour, afterwhich the material is removed, rinsed and dried. The treated cloth isbrightened to a high degree in contrast to untreated cloth.

The 4' chloro 4 [2-(2H-naphtho[1,2]triazolyl)]-2- stilbenecarbonylchloride utilized in this example is prepared by adding 130 grams of4chloro-4-[2-(2H-naphtho [1,2]triazolyl)]-2-stilbenecarboxylic acid to amixture of 350 grams of thionyl chloride and 1 gram of pyridine. Afterstirring for 5 hours at -95 C., the excess thionyl chloride is distilledunder reduced pressure and the solid residue of the acid chloride weighs130 g. and melts at 187.8 190.0 C. uncorrected.

The preparation of 4'-chloro-4-[2-(2H-naphtho[1,2]triazolyl)]-2-stilbenecarboxylic acid is as follows:

To a solution of 159 grams of 4-amino-4'-chloro-2- stilbene-carboxylicacid in 2400 cc. of glacial acetic acid is added 304 cc. of concentratedhydrochloric acid and 1500 cc. of water. The mixture is cooled to 0 C.and a solution of 41 grams of sodium nitrite in cc. of water is added toeffect the diazotization. After stirring for 30 minutes at 0 C.-5 C.,the excess of nitrous acid is reacted with enough sulfamic acid to givea negative test for nitrite on starch-iodide paper. A warm solution of92.2 grams of 2-naphthylamine in 1500 cc. of water containing 68 cc. ofconcentrated hydrochloric acid is added gradually to the diazo solutionmaintained at 5 to 10 C. The coupling reaction is completed by addingover a period of 1 hour 864 grams of sodium acetate trihydrate followedby stirring of the mixture for 16 hours. The precipitated o-aminoazodyestufi is separated by suction filtration and washed thoroughly on thefunnel with warm (60 C.) water to give 700 grams of wet filter cake.

The entire wet cake of dye is dissolved at 95 C. in 3000 cc. of mixedpicolines and treated with a solution of 362 grams cupric sulfatepentahydrate in 725 cc. of water. After stirring the mixture for 2 hoursat the refiux temperature, a solution of 116 grams of sodium sulfideflakes in 500 cc. of water is added. The charge is clarified at 90 C. toremove the copper sulfide precipitate. The clear filtrate is treatedwith aqueous sodium hydroxide solution to pH 10 and then distilled withsteam to separate the picoline. The product is filtered from the residueafter the steam distillation, slurried in 6000 cc. of water at 90 C. andtreated with concentrated hydrochloric acid to Congo blue acidity. Afterfiltering and washing the filter cake free of acid with water, thematerial is dried at C. under reduced pressure to give 200 grams of4'-chloro-4- [2-(2H-naphtho[1,2]triazolyl)]-2-stilbenecarboxylic acid, ayellow powder which melted at 274-275.8 C. uncorrected.

The 4-amino-4'-chloro-2-stilbenecarboxylic acid used above is obtainedas follows:

A solution of 200 grams of 4'-chloro-4*nitro-2-stilbenecarboxylic acid[prepared from 4-chlorobenzaldehyde and S-nitro-o-toluamide by themethod of Macovski, Georgescu and Bachmeyer, Ber., 748, 1279-84 (1941);Chem. Abstracts, 36, 4813 (1942)] in 540 grams of N,N-dimethylformamideis reduced with 200 grams of iron borings etched with 50 grams ofconcentrated hydrochloric acid in 300 grams of water containing 800grams of N,N-dimethylformamide.

By employing the reaction conditions given in Example IX, the brightener2,4-dichloro-N-(3-morpholino)-ethyl- 4[2I-I-naphtho-[1,2]triazolyl)]-2-stilbenecarbonamide is prepared from12.8 grams of 2-morpholinoethylamine and 23.9 grams of2',4-dichloro-4-[Z-(ZH-naphtho[1,2]triazolyl)]-2-stilbenecarbonylchloride (obtained by condensing 2,4 dichlorobenzaldehyde with-nitro-o-toluamide according to Macovski, Georgescu and Bachmeyer, Ber.,748, 1279-84 (1941); Chem. Abstracts, 36, 4813 (1942) to produce2',4-dichloro-4nitro-2-stilbenecarboxylic acid (M.P. 256.l259.9 C.)which is then reduced to the amine, diazotized and coupled to2-naphthylamine, oxidized to the triazole and treated withthionylchloride as shown in Example IX.

The resulting brightener is applied to Orlon in the same manner as inExample IX. The treated cloth has much greater brightness than theuntreated cloth.

EXAMPLE XI CHrCH:

CONHCsHrN O CHsC 1 EXAMPLE XII p-Tolualdehyde is condensed with 5-nitroo-toluamide to produce 4'-methyl-4-nitro-2-stilbene-carboxylic acid[(method of Macovski, Georgescu and Bachmeyer, Ber., 74B, 1279-84(1942); Chem. Abstracts, 36, 4813 (1942 In the manner given in ExampleDC, the nitrostilbene is reduced, diazotized and coupled to2-naphthylamine, oxidized with cupric sulfate to form the triazole andfinally treated with thionyl chloride which yields 4'-methyl-4-[2- (2Hnaphtho[1,2]triazolyl)]-2-stilbenecarbony1chloride as a yellow powder.

65 grams of the 4'-methyl-4-[2-(2H-naphtho[1,2]triazolyl)]-2stilbenecarbonyl chloride prepared as above are condensedwith 33 grams of diethylamine while following the procedure of ExampleDC.

The resulting brightener is applied to a polyester fiber (Dacron) asfollows: 50 mg. of brightener are dissolved in 100 cc. of dimethylformamide. 5 cc. of this solution are added to 145 cc. of 0.1% Peregal 0aqueous solution. Peregal O is a polyoxyethylene condensation sur- 14factant. A 5.0 gram swatch of Dacron is introduced and the dyebathheated to 190200 F. for 1 hour with agitation. The cloth is removed,rinsed and dried. The treated cloth shows a much greater whiteness thanuntreated cloth.

EXAMPLE XIII /T N ooNHcHmHmwHm N l By using 39.6 grams of2-(N,N-dimethylamino)ethyl amine in place of 33 grams of diethylamine inExample XII, the brightener N-[2-(N,N-dimethylamine)]ethyl 4'-methy1-4-[2-(2H naphtho[1,2]triazoly1)]-2-stilbenecarbonamide isprepared.

The brightener is applied on polyacrylonitrile fiber (Orlon) by themethod given in Example IX. The treated fabric is much whiter than theuntreated Orlon swatch.

EXAMPLE XIV A mixture of 67 grams of 4'-chloro-4-[2-(2H-naphtho[1,2]triazolyl)]-2-stilbenecarbonyl chloride (prepared in Example IX),78 grams of di-n-butylamine and 800 grams of toluene is allowed to reactas described in Example IX to give 46 grams of4-chloro-N-(di-n-butyl)-4-[2- (2H naphtho[l,2]triazolyl)]Z-stilbenecarbonamide, M.P. 176.2 C.177.1 C. uncorrected.

The brightener is applied on polyamide fiber (nylon) using the methodgiven in Example XII for application of a brightener to polyester(Dacron). The treated nylon swatch appears considerably whiter whencompared with the untreated swatch.

EXAMPLE XV omen,

A mixture of 41 grams of 4-[2-(2H-naphtho[1,2]triazolyl)]-2-stilbenecarbonyl chloride, 25 grams of morpholine and 500grams of toluene is heated for 6 hours at C. After evaporation of thetoluene, the residue is washed with water and recrystallized from 200grams of ethanol to yield 4-[2-(2H-naphtho[1,2]triazolyl)]-2-stilbenecarbonylmorpholine as a yellow powder.

The compound 4-[2-(2H-naphtho[1,2]triazolyl)]-2- stilbenecarbonylchloride is synthesized according to the procedure described in ExampleD( for the preparation of 4'ch1oro-4-[2-(2H-naphtho[1,2]triazolyl)]1-2-stilbenecarbonyl chloridestarting from 36.4 grams of 4-nitro-2- stilbenecarboxylic acid (obtainedfrom benzaldehyde and the methyl ester of S-nitro-o-toluic acidaccording to the method of Pfeifier and Matton, Ber. 44, 1119).

The brightener is applied to both polyester (Dacron) and polyamide(nylon) fibers in the manner given in Example XII for the application ofa brightener to polyester fiber. In each case, the fabric treated withbrightener appears much whiter than the untreated fabric.

1 EXAMPLE Xvr A mixture of 270 grams of 4 methoxybenzaldehyde, 360 gramsof S-nitro-o-toluamide and 12 grams of sodium methylate dissolved in2500 grams of methanol is allowed to react in accordance with the methodof Macovski, Georgescu and Bachmeyer, Ber. 74B, 1279-84 (1941) toproduce 4-methoxy-4-nitro-2-stilbenecarboxylic acid.

By substituting 187 grams of 4'-methoxy-4-nitro-2-stilbene-carboxylicacid for 200 grams of 4-chlor0-4-nitro- 2-stilbene-carboxylic acid inthe reduction step in Example IX, and then continuing as described inExample IX with the diazotization, coupling to Z-naphthylamine,oxidation and subsequent reaction of the triazole compound with thionylchloride, the 4'-methoxy-4-[2-(2H- naphtho[l,2]triazolyl)] 2stilbenecarbonyl chloride formed is treated with morpholine in themanner described in Example XV to give the brightener 4'-methoxy- 4 [2(2H-naphtho[1,2]triazolyl)]-2-stilbenecarbonylmorpholine.

The brightener is applied to both polyamide (nylon) and polyester(Dacron) fibers in the manner referred to in Example XII. The treatednylon and Dacron fabrics are whiter in appearance than the untreatedfabrics.

EXAMPLE XVII grams of dimethyl terephthalate, 4.85 grams of ethyleneglycol and 0.003 gram of metallic sodium, as a catalyst, are heated for3 hours at 200 C. in a stream of pure nitrogen. At the end of 3 hours,0.30 gram of the brightener of Example I are added to the resultingpolymer. The low molecular weight polymer is then heated at 280 C. for30 minutes, then further heated for 10 hours in a vacuum. During theheat conversion a slow current of nitrogen is introduced through acapillary tube. The final product melts at 260 C. The methyl alcoholformed as a by-product of the ester interchange is removed during theheating period. The final product as formed is extruded in molten formas a ribbon cooled with a water spray, then cut into chips. The chipsare melted in the absence of air and water, then extruded throughorifices to give them the desired shape. The shaped articles can beconverted into fibres in continuous filament form or cut into shortsegments as staple. Both filaments and short segments showed anoticeable whitening effect. The same results are obtained with thebrighteners of Examples II to XVI, inclusive.

EXAMPLE XVIII To 10 grams of Dacron polyester cloth in an aqueous bathof 200 mls. volume at 90 C. is added a solution of 0.002 gram ofbrightener of Example I in 5 mls. of dimethyl-formamide. The polyestercloth in the bath is agitated for 1 hour, after which it is removed fromthe bath, rinsed with water, and dried. It is then further heated in anoven for 2 hours at 200 C., and then cooled to room temperature. Theheat setting at 200 C. causes migration of the brightener into the fiberand produces a whitening effect thereby. The Dacron in this operation isbrought to a temperature just below its softening point so that itbecomes necessary to adapt the process to the particular polyester athand. This example illustrates a transition case between a true meltapplication and the textile applications at lower temperatures.

16 We claim: 1. A fluorescent naphthotriazole compound of the classselected from the group consisting of those of the following formulae:

CONH- a N CON-(R4): N

wherein R and R represent a member selected from the class consisting ofhydrogen, halogen, lower alkyl and lower alkoxy, R represents a memberselected from the class consisting of hydrogen, lower alkyl, lowerhydroxy alkyl, dialkylamino alkyl of from 3 to 16 carbon atoms,morpholinoN-alkyl and piperidino-N-alkyl wherein the alkyl groupcontains from 1 to 4 carbon atoms, R., represents a member selected fromthe class consisting of a lower alkyl and lower hydroxy alkyl group, andR represents the atoms necessary to complete with the nitrogen atom aheterocyclic ring system selected from the class consisting of 5- and6-membered ring system.

2. A compound as defined in claim 1 wherein R is hydrogen.

3. The compound of the formula:

4. The compound of the formula:

5. The compound of the formula:

1 as N/ t? \J 1 7 6. The compound of the formula:

N CH,@CH=CH N ONE, N

7. The compound of the formula:

@CHH N/T 8. The compound of the formula:

-CH I N G 9. The compound of the formula:

C1 CH=CH N CHr-CH:

CONH(CH:)N /O CHz-CH:

18 10. The compound of the formula:

CHI-CH, 0 ON 0 CHg-Cflz 11. The compound of the formula:

W CMH NQ 12. The compound of the formula:

J] ON (lb-C 119): N I

References Cited UNITED STATES PATENTS JOHN D. RANDOLPH, PrimaryExaminer.

WALTER A. MODANCE, Examiner.

1. A FLUORESCENT NAPTHOTRIAZOLE COMPOUND OF THE CLASS SELECTED FROM THE GROUP CONSISTING OF THOSE OF THE FOLLOWING FORMULAE: 